I just started my tank last week. After a few days I added 5 platy's. All but one adapted quickly to the tank. The other was alienating himself, sitting on the bottom of the tank and not eating. It got worse, his fins are all clamped down and I noticed some faint white spots (barely noticable, on the fins) as well as a thin whitish feces (though this could be because he isn't eating!). He just sits on the bottom, and now I have seen him rubbing up against the decor & gravel. I took him out and into a hospital tank. Now, another fish is rubbing himself against the decor & gravel (none of the other symptoms have appeared in the second one yet). What do I do?? Is this normal, is he just scared? What does it mean when fish start rubbing against the decor & gravel?